Over the years, there have been many devices proposed that utilize a light source in connection with a hand tool. Screwdrivers have had light bulbs incorporated therein with the light projecting therefrom either along the axis of the screwdriver or offset from the axis. Even flashlights have been provided with tool bits mounted on the head thereof to assist the user by providing light directed at the workpiece.
It is often desirable to have an additional source of light that can be directed at the work area. Many times a mechanic must work in confined spaces with little available light. Automobile engines often have bolts located in the nooks and crannies of the engine and the ambient or overhead light in the garage area is just not sufficient to illuminate the work space so that the bolt is readily visible to the mechanic. Some mechanics try and use a wrench in one hand and a flashlight in the other hand to shine light into the work area where the bolt is located. However, many times it is necessary to use both hands on the wrench, especially when socket wrenches with extensions are used. It is therefore desirable to have a light source incorporated directly into the work tool, particularly into a socket wrench, so that the light needed to illuminate the work area can be projected directly from the tool and onto the bolt.
To achieve this desired result, ratchet-type wrenches have been provided with light sources to illuminate the work area. U.S. Pat. No. 4,324,158 (Le Roy) discloses a ratchet-type wrench that has a light bulb positioned in the handle of the socket wrench. This patent discloses a conventional ratchet-type socket wrench that has the handle area hollowed out to receive one or more batteries to provide a power supply for a light bulb. In one embodiment, the light bulb is mounted in the lug of the ratchet head with an opening provided in the face of the lug to allow the light from the light bulb to be directed into the work area. Wires connect the light bulb to the batteries and the handle of the socket wrench includes a switch to turn the light bulb on and off.
The Le Roy patent also shows an embodiment in which the light bulb is mounted in a swivelable assembly just below the head of the socket wrench. This allows the light bulb to be rotated to vary the angle at which the light is directed into the work area.
The Le Roy patent does not solve the problem of directing light to the work area when a socket extension is needed on the socket wrench. Often when using a socket wrench, the mechanic must still access a bolt that is in a tight location and the head of the socket wrench cannot reach the head of the bolt. In such a situation, it would be helpful to have a light source physically located in the socket extension so that the light can be directed onto the head of the bolt even when the bolt is located a distance from the head of the socket wrench.
U.S. Pat. No. 4,253,134 to Barnaby discloses a socket wrench extension that incorporates a light bulb, one or more batteries and a control switch in the hollow interior thereof. The socket extension is hollow throughout and has a handle receiving end that receives the lug on the head of the socket wrench handle. The other end of the hollow extension receives the socket of the size needed to interact with the bolt head. Intermediate the two ends of the extension is a hollow space that contains the light bulb, one or more batteries and a switch. The light bulb is mounted in a bulb plug and is set back from the end of the socket extension. The end of the socket extension also has a lens covering the end opening to protect the light bulb from grease or oil and which permits easy cleaning of the lens. One or more dry cell batteries are aligned in the hollow interior of the extension behind the light bulb with the end contact of the battery in contact with the end of the light bulb to provide an electrical connection. A contact switch is mounted adjacent the handle receiving end of the extension. The contact switch is carried by a plastic housing that is screwed into the handle receiving end of the extension. A spring is provided between the end of the battery and the contact plug to bias the contact plug away from the battery. When the lug of the socket head is connected to the handle receiving end of the extension, the force of the lug on the contact plug pushes the contact plug into electrical contact with the end of the battery. This completes the electrical circuit and causes the light to illuminate.
The drawback of the Barnaby device is that the amount of space required in the hollow interior of the extension structurally weakens the extension and limits the size of sockets that could practically be used as well as limits the amount of torque that can be applied to the bolt head.
Another socket extension that includes a light source on the hollow interior thereof is disclosed in U.S. Pat. No. 5,477,434 to Reed. Similar to the Barnaby configuration, the Reed device has a hollow socket extension with one open end for receiving the lug from the head of a socket handle and another open end for receiving the socket. The Reed extension is hollow throughout and has mounted in the interior thereof a light assembly which is carried within a tubular casing made of an electrically insulating material such as plastic. The components of the light assembly are a light bulb, a coil spring, a battery and a push button. Once these components are assembled within the tubular casing, the ends of the tubular casing are rolled over to form thickened rims to narrow the interior opening and to retain the components of the light assembly inside the tubular casing. The coil spring is biased to keep the battery away from the light bulb when light is not needed. The push button is a T-shaped member with its flat end resting against the end of the battery. When the lug of the socket head is inserted into the socket extension, the end of the lug engages the push button and forces the push button firmly against the battery. This forces the battery to move along the interior of the extension and the end contact of the battery comes into contact with the electrical contact on the end of the light bulb. This provides electrical current to the light bulb causing it to illuminate.
One drawback of the Reed configuration is that all of the components of the light assembly are encapsulated inside the tubular casing once the ends are rolled over. Thus, if one of the components needs to be replaced, e.g. the battery expires or the light bulb burns out, there is no way to replace the single nonworking component. In the Reed configuration, the entire light assembly including the surrounding tubular casing must be replaced if one component becomes non-functioning. This creates an unnecessary expense to the mechanic, especially since the light assembly encapsulated within the plastic casing is not readily available at the local hardware store and, no doubt, must be obtained directly from the manufacturer.
It is an object of the present invention to provide, for use with a socket wrench assembly, a socket extension with an internal light source in which either the battery or the light bulb can be separately replaced. It is a further object of the present invention to provide a novel structure for the light assembly.
It is a feature of the present invention that the construction of the socket extension allows the components of the internal light assembly to be easily disassembled so that either the light bulb or the battery can be replaced when needed. The light assembly includes a light mounting disk that protects the light bulb and light bulb holder from being harmed by any leakage from the battery.
It is an advantage of the present invention that each component of the internal light assembly can be replaced when needed rather than incurring the unnecessary expense of replacing the entire internal light assembly when only one component thereof needs replacement.
Other objects, features and advantages of the present invention will become apparent from a consideration of the following detailed description.